A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image is a design of blue glass.How about using it as background image?
Source Yamachem
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Light and tiny, just the way you like it.
Source Rohit Arun Rao